Fifth case confirmed in South African viral outbreak

Oct 28, 2008 (CIDRAP News) – A fifth case has been confirmed in the recent outbreak of febrile illnesses caused by a mysterious virus in South Africa, and preliminary tests have supported earlier suspicions that it is new member of the arenavirus family, South African health officials announced recently.

A worker who fell ill and died after cleaning a hospital room where the first case-patient in the outbreak had stayed was confirmed to have the virus, South Africa's National Institute for Communicable Diseases (NICD) said in an Oct 24 update.

The cleaner, a woman named Maria Mokubong, died Oct 6, according to a report today by the Independent Online, a South African news service.

Three other people had died of the virus earlier. The first was a Zambian woman who fell ill during a safari in South Africa. Subsequently a paramedic who helped care for the Zambian woman during her transfer to a Johannesburg hospital and a nurse who cared for the same patient during her hospitalization succumbed to the virus.

Another nurse, who helped take care of the paramedic, also got sick but has so far survived. Melinda Pelser, a spokeswoman for Morningside Medi-Clinic in Johannesburg, where the nurse works and is being treated, said she was in serious condition but "on the road to recovery," according to the Independent Online report.

The NICD said tests by its own laboratory and the US Centers for Disease Control and Prevention (CDC) have confirmed an Old World arenavirus in all five cases. An analysis of genetic sequence data generated by the NICD, the CDC, and Columbia University in New York City "appears to indicate that the current outbreak is caused by a unique Old World arenavirus," the NICD statement said.

"Preliminary testing indicates that the virus associated with the present nosocomial outbreak is a distinct new member of the family," the NICD added.

The agency said there were no more suspected cases in the outbreak. The number of people being monitored because of possible exposure to the patients has dropped from 94 to 31, according to the Independent Online.

Arenaviruses are carried by rodents and secreted in their urine. Recognized "Old World" arenaviruses include lymphocytic choriomeningitis virus (which actually occurs worldwide) and Lassa fever virus, which affects as many as 500,000 people annually in West Africa, the NICD said. Several arenaviruses found in South America, including Junin, Machupo, Sabia, and Guanarito viruses, cause a hemorrhagic fever syndrome, the statement noted.

The hospital cleaner who died of the infection was bleeding and confused when she presented for treatment, and she died soon afterward, the NICD said. The agency gave the following clinical profile for the other patients:

All initially presented with an influenza-like illness including fever, headache, and muscle aches.

The illness worsened in the course of a week, with all four patients suffering diarrhea, sore throat, and a rash on the face and throat. Three patients also had facial swelling.

In the fatal cases, the illness lasted 9 to 12 days, culminating in sudden deterioration with respiratory distress, neurologic signs, and circulatory collapse.

"Bleeding was not a prominent feature," but one patient had a petechial rash, and another had oozing of blood from venipuncture sites.